How about this, who would you add that isn't an all-NBA level player?
There are lots of good options. For this particular team, I'd say Sabonis would be a great fit. I also like the Mobley option, although I wish he'd start hitting his threes.
I get Sabonis is unlikely to make an All NBA Team (though he would have a good shot at 3rd center), but I have a hard time calling a guy averaging just under 19/12.5/7 with a TS% of 68.4 as someone that isn't an all-NBA level player. Same with young guys like Banchero and Mobley that clearly have All-NBA level talent they just haven't fully matured yet.
I mean Brown has never made an All-NBA team and I think he is unlikely to do so this year as well (Doncic, Mitchell, Morant, SGA, Young, Harden, Irving, Haliburton, Booker, Edwards, Garland, etc. - i.e. lots of competition at guard), but I don't think that he would hypothetically be available in that reduced window.
Short term I think someone like Valanciunas would be a solid fit of a guy that is pretty clearly not an All-NBA level talent. If I was looking for a bit more offensive pop I'd look at Markkanen or Randle.